In laparoscopic surgery, a number of small holes are opened in a patient's abdomen or the like, and an endoscope, a forceps (or manipulator) or the like is inserted, and surgery is carried out while the surgeon observes an image from the endoscope on a monitor. In this type of laparoscopic surgery, owing to the fact that opening of the abdominal cavity is unnecessary, the burden on the patient is small, and the number of days required for the post-operative recovery and the number of days spent in the hospital can be significantly reduced. Therefore, laparoscopic surgical operations are expected to find an increased range of applications.
A manipulator system, for example, as disclosed in Japanese Laid-Open Patent Publication No. 2004-105451, comprises a manipulator main body, and a controller for controlling the main body. The manipulator main body comprises an operation command unit, which is operable by hand, and a working unit, which is detachable and exchangeable with respect to the operation command unit.
The working unit (tool) includes an elongate connecting shaft, and a distal end working unit (also referred to as an “end effector”) disposed at the end of the connecting shaft. One or more actuators (motors) are disposed in an operation command unit for driving the working unit by means of wires. The wires are wound around pulleys at a proximal end side. The controller drives the motors disposed in the operation command unit, and also drives the wires in an advancing/retracting manner via the pulleys.
The working unit is constructed so as to be detachable with respect to the operation command unit in order to enable cleaning to be carried out easily following completion of a surgical technique. Further, in laparoscopic surgery, various different types of working units are used depending on the surgery involved. A gripper, scissors, an electrical knife, an ultrasonic knife, a surgical drill or the like may be given as examples thereof. From the standpoint of being able to exchange these working units, a structure in which the working unit is detachable with respect to the operation command unit also is beneficial.
In the working unit, proximal end side pulleys thereof are constructed so as to engage with the rotational shafts of motors, which are disposed in the operation command unit.
By detaching and removing the working unit from the operation command unit, cleaning processing performed on the working unit becomes considerably easier. However, it would also be desirable for cleaning of the mechanisms, such as pulleys and gears or the like, which are disposed within the proximal end side, and in the distal end working unit (end effector) part of the working unit, to be conducted more easily.
The pulleys and gears are connected by wires within the working unit, whereby motive forces are transmitted thereby. It is desired to easily and reliably transmit motive forces through such pulleys, gears, and wires.